There have been very few community-based studies of progression of Alzheimer's disease (AD) and none have used incident dementia patients. In addition, the later consequences of disease progression are rarely addressed. We proposed to prospectively follow 500 ethnically diverse patients with probable or possible AD (150 incident dementia cases and 350 prevalent dementia cases) already identified from a stratified random sample of elders in a defined region of North Manhattan in order to test specific hypotheses regarding determinants of disease course and outcomes. We will determine the timing and occurrence of specific disease endpoints such as acute hospitalization, change in CDR score, admission to nursing home (or its equivalent) and mortality. We will also characterize rapidity of disease course in more advanced AD by applying perform activities of daily living. We will explore factors hypothesized to be associated with increased relative risk for the occurrence of the disease endpoints or with more rapid disease course, including: gender, age and estimated age at onset; comorbid medical factors such as stroke, cerebrovascular risk factors, extrapyramidal signs and myoclonus, cardiovascular disease, diabetes, malnutrition and cachexia; sociocultural factors including race/ethnicity, education, lifetime occupation, and family SES; behavioral manifestations including psychosis and agitation; and, for incident dementia, biomedical risk factors as well as the rate of cognitive and functional decline prior to the incident dementia. We will also compare mortality in demented patients to that observed in nondemented community patients matched for age, sex and other relevant variables. We hypothesize that: there will be a higher relative risk for reaching disease endpoints associated wit male gender, more advanced age at onset, more severe dementia and specific comorbid medical factors; sociocultural factors will influence disease course through their association with comorbid medical factors and with differences in service utilization and perceived functional disability; patients with lower educational and occupational attainment will have longer survival times; and dementia will be associated with increased mortality relative to the nondemented population.